Spunbond nonwovens are widely used in various end use applications such as hygiene, medical, industrial, or automotive applications to provide low basis weight, economical, strong, and cloth-like fabrics. The spunbond nonwoven fabrics typically comprise monocomponent or bicomponent fibers. Bicomponent fibers include, for example, core/sheath, segmented pie, side-by-side, islands in the sea, and the like. A common bicomponent fiber configuration is a core-sheath structure, wherein the core comprises homopolymer polypropylene and the sheath comprises polyethylene. The core-sheath provides drawdown capability, spinning stability, heat resistance, modulus, ultimate tensile strength inherent to polypropylene, while providing the added feature of soft touch, lower bonding temperatures, and higher elongation attributed to the addition of the polyethylene sheath. While bicomponent structures such as core/sheath are gaining popularity particularly in health and medical applications, where consumers demand articles such as feminine hygiene products, diapers, training pants, adult incontinence articles, and medical drapes and gowns to have a soft touch and improved fit. However, drawbacks of bicomponent fibers include the increased cost to purchase and install a bicomponent line versus a monocomponent line, the increased complexity of using multiple resins, the reduced capability to incorporate recycle edge trim from the fabrics due to the incompatibility of the polyethylene and polypropylene, and the reduction in throughput.
Accordingly, there is a need to improve softness of spunbond nonwoven fabrics comprising monocomponent fibers while maintaining other key performance attributes such as fabric strength and processability.